Signal



P. H. CHASE Sept. 3, 1940.

SIGNAL gli g2 FIGB.

Sept. 3, 1940.

P. H. CHASE S IGNAL Filed June 5, 1937',

2 Sheets-Sheet 2 Patented Sept. 3, 1940 UNITED i-.ENT GFFCE SIGNALPhilip H. Chase, Bala-Cynwyd, Pa.

Application June 5, 1937, Serial No. 146,582

9 Claims.

This invention relates to signals and with regard to certain more specicfeatures to a directcurrent, light signal system.

This application is a continuation--in-part of my application, SerialNo. 689,556, iiled September 15, 1933 for Signal, eventuated into PatentNo. 2,082,789, dated June 8, 1937.

Among the several objects of the invention may be noted the provision ofa signal light which by recurring variations in light intensity morequickly attracts the attention of the observer; the provision ci a moreeiiective stop and/er direction signal light; the provision of means forrecurrently varying signal light brightness Without opening the signalcircuit; the provision of a pilot lamp which indicates the operation andcondition of the system; the provision of a variably modulated lightsignal; the pro- Vision of eiTective signal lamp operation in the eventof burn-outof the pilot lamp and/cr the stoppage oi certain ci theapparatus; and the provision of a multiple-purpose system wherein asingle lamp aords illumination and a signal. Other objects will be inpart obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations ofelements, features of construction, and arrangements of parts which willbe exemplied in the structure and circuits hereinafter described, andthe scope of the application of which will be indicated in the followingclaims.

In the accompanying drawings, in which are illustrated several ofvarious possible embodiments of the invention:

Fig. 1 is a diagrammatic layout of one form of the invention;

Fig. 2 is a diagram showing a contacter device of the type that may beused in Fig. 1;

Fig. 8 is a diagrammatic layoutl of a modification of the form ofcircuit shown in Fig. l;

Fig. 4 is a diagram illustrating a modification of the form of thecircuit shown in Fig. 3; and,

p Fig. 5 illustrates a combined contacter and interrupter device adaptedto be used with the embodiments shown in Figs. 3 and 4.

Similar reference characters indicate correspending parts throughout theseveral views of the drawings.

Fig. 1 herein substantially corresponds to Fig. 19 of my saidapplication, Serial No. 689,556 (Patent 2,082,789) and in fact is almostidentical with said Fig. 19 oi said application, with exception offormalities.

It is knownv practice to mount on the rear of a motor vehicle anelectric stop signal which is lighted upon the application of thebrakes, by the closing of a switch actuated from the foot brakemechanism. It thus gives a signal 5 often anticipatory of the slowingand complete stopping of the vehicle. Such a stop light signal isusually contained in or adjacent to the electric rear light housing,often is the same color as the tail light, and sometimes consists of oneoi the iilaments in a two-filament lamp, the other filament being usedfor the tail light.

Consequently, the eiiicacy of the usual stop iight signal is greatlyreduced, particularly at night, because once it is lighted it is usuallyun- 15 changing and may be similar in appearance to the tail light. Itdoes not continue tc give an unmis'taliably distinctive signal warningthat a vehicle is slowing, stopping, or has stopped.

The practice of signalling left and right turns. by hand is littleobserved and when done, often escapes notice, or is not understood. Suchhand signals are usually inconvenient to the driver of a closed vehicle,particularly during inclement weather. Electric direction signals of theusual types are subject to similar diiculties as the stop light.

The provision of means for causing the dickering or blinking of stop anddirection light signals may afford a warning signal diiierent from thetail light, but these results have often been secured at the expense ofadded complications and liability oi complete impairment of operation ofthe signal devices, and, among certain other disadvantages, omit meansindicating to the vehicle driver the operation and condition of thesignal system.

The present invention secures the advantages of a controlled modulatedsignal by relatively simple apparatus, and provides for the inclusion ofa pilot lamp when desired, under the eyes of the driver, or of anotheroccupant of the vehicle, which indicates the operation and condition oi"the signal system.

It is to be understood that the method and apparatus oi the presentinvention is useful in other applications than to vehicles; for example,on crossing gates, traffic signals, switchboard signals and the like,wherein similar requirements may exist. The vehicle application is usedmerely by Way of example.

M odiyicaton of Fig. 1

Referring now more particularly to Figure 1, there is illustrated atnumeral I an electric signal lamp with iilament il, connected by wire7l, in series with one-way electric valve 2i l, and resistor lflll, wire9S, switch 52 and wire 9| to a battery 6d. The signal lamp circuit iscompleted by wires 92, 99 and lit. l

For example, as applied to a motor vehicle, the signal lamp i may be asix to eight volt tungsten iilament automobile type lamp of three tothirtytwo rated candle power; the switch 52 may be actuated, forexample, by the foot-brake mechanism to close the switch when the brakepedal is depressed in case the signal lamp is for a stop warning, or theswitch may be actuated manually in case the signal lamp is for adirection signal; the battery may be the usual lead storage battery, andthe wire 99 may be replaced by the metal frame of the vehicle.

The lone-way electric valve 2M, such, for example, as a copperoxide-copper rectifier, is connected so that the signal lamp currentfrom the battery @il will pass through it but substantially no currentcan pass in the opposite direction. The resistor lili) may be omitted incase the resistance of the valve alone is sucient and in case novariable modulation effect afforded by the resistor is desired.Alternatively, under some conditions the valve 2M may be omitted.

An auxiliary battery 62 is in series with the contacts 3l, 32 oi thecontactor 2t and in parallel with (shunting) valve 24|! and resistor|253, and is connected so that its voltage aids or adds to that of themain battery l.'

The con'tactor device 2i! (see also Figure 2) recurrently closes andopens the contacts 3| and t2, at a` frequency within a suitable range,so long as switch 52 remains closed.

As generally applied to the usual types and sizes of automobile electriclamps, the frequency oi closing the contacts should preferably fallbetween two and ten per second, because of the relation of persistenceoi vision and lag in filament incandescence and cooling to desirablevariability or modulation of light from the signal lamp, but thefrequency for a given signal device need not remain constant and, insome embodiments, it may be desirable for it to vary, for example, withthe speed of the vehicle.

When switch 52 is closed, and contacts 3l, 32 are open, the signal lampcurrent passes through valve 24| and resistor Mt, and the voltage on thesignal lamp is the voltageof main battery Si! less the drop throughvalve 24E, resistor lill] and the connection therewith. The totalresistance of the valve and/ or resistor may be oi such value thatsignal lamp brightness is only little, or substantially less (but stilldistinctly visible) than if the valve and resistor were omitted. After afraction of a second, contacts 3l, 32 close and connect battery 62 inseries with and aiding the main battery 6G, thus increasing the voltageon the signal lamp circuit to the sum of the two battery voltages andincreasing the signal lamp brightness above that corresponding to supplyfrom only the main battery Eil. Ii the valve 2M is omitted, the currentthrough battery 62 is the algebraic sum of the signal lamp current andof Vthe current through the resistor i463, but if, as is preferable, thevalve is included, the current through the battery 62 is only that ofthe signal lamp under the total voltage.

While contacts Sl-BZ are closed, with valve 24| included, there is nocurrent flow through resistor |423. Though the inclusion of aidingbattery 62 in the signal circuit tends to reverse the directionofcurrent through the resistor lll, the

valve 24| prevents such flow. The purpose of valve 24| is to prevent theadded load on battery 62 of a reverse current through resistor |40. Withvalve 24| omitted reverse flow of current `takes place and the currentthrough battery 62 is the sum of the signal lamp current and the currentthrough resistor Mil. It is clear'that such reverse current flow existsonly while contacts .3l-32 are closed, usually only during the shortperiods the signalling equipment is in opreration. Further,A the amountof the reverse current flow through resistor |49 is determined by f thesum of its resistance and the resistances of resistor lill and valve262. However, if valve 24| is omitted, the value of resistor it@ will bemade such as to limit the current therethrough to values suited to thebattery 52, and avoid attaining a short-circuit value.

For example, it has been found on a signal lamp circuit, such as isusually employed on an automobile that, with a 6 volt main battery' 6i),a 21 candle power 6-8 volt tungsten lamp, an auxiliary battery voltageof 2 volts and a valve and resistor of 1.2 ohms total resistance orless, there ,is a modulation which aords a distinctive signal. Thuswhile the contacts 3|-32 are open the signal lamp current passes throughresistor |46 and would be about 1.75 amperes, corresponding to 3.9 voltson lamp 4, that is, 6 volts less the IR drop through resistor Ulli, theresistance ci valve 24| being negligible. With contacts 3|-32 closed,valve 24| omitted, and the resistor IM) of a value of 1.2 ohms, thetotal current through the auxiliary battery 62 would be approximately4.42 amperes. This is the sum of about 2.75 amperes lamp current and1.67 amperes reverse current through resistor |40, with both resistor lland valve 24| omitted, or, if resistance lill is included its resistanceassumed to be negligible. The value 2.75 amperes corresponds to 8 voltson the lamp f3, which is 6 volts from the battery 66 plus 2 volts frombattery 62. The value of 4.42 amperes is not a short-circuit value forbattery 62 which together with battery 60 delivers 2.75 amperes for thesignal lamp. This 2.75 amperes is the value of current with valve 24|included and also if valve 24| is omitted.

In the shunting or parallel circuit is also included resistor |4| andvalve 242, although these may be omitted. Under some conditions aresistor such as liti may be useful in regulating the modulationproduced by the auxiliary batte-ry or generator. The valve 242 may beuseful under some conditions; for example, to prevent current reversalthrough the auxiliary source, or to provide modulation only in adirection aiding the main battery in case the auxiliary source isalternating current.

A direct-current generator |6| is illustrated in parallel with theauxiliary battery, but may be replaced by any other suitable means forcharging the battery 62, if it is a storage battery. On the other hand,if, for example, it is` tor.

A pilot lamp l l is included in the embodiment of Figure 1, for example,in parallel with resistor |40 and Valve 24|, and numeral l2 indicates apilot lamp connected in parallel with the signal lamp.

The contactar device of Fig. 2 (for use in Fig. 1)

An example of the character of the contactor device 2G that may be usedas lindicated in Figure 1 is illustrated in Figure 2. A coil 2| is woundabout a magnetic core 22, which is associated with an armature 23pivoted at 24, with an extension 25 on which is mounted a counterweight26. The armature is normally retracted from the ycore 22 by a spring2l'. The armature 23 is adapted to make contact with contact 33 when thearmature is retracted as shown and, when the armature moves toward thecore 22, to break the contact with 33.

Upon closing of switch 52, in addition to the current passing throughwire 90, resistor |40, valve 24|, and wire 1| to the signal lamp l, thecurrent for the shunt coil 2| passes through wire 33, coil 2|, contact33, armature 23 and back t0 the battery through wires 98, S9 and 92, andmagnetic flux is produced through the core and armature.

An extension 36 is relatively insulated as at 34 from and operated bythe armature, so that when the armature moves toward the core itconnects contacts 3| and 32.

By the attraction of the armature 23, the restraining force of spring 2lis overcome, the armature 23 moves downward, contact is broken betweenarmature and contact 33, and contact is made by extension 36 betweencontacts 3| and 32.

Immediately upon the opening of the circuit through coil 2| by theaforesaid breaking of contact between armature 23 and contact 33, themagnetic flux through the core 22 and armature 23 rapidly decreases, thespring 27 retracts the armature, contact is broken between contacts 3|and 32, and then contact is re-established between armature 23 andcontact 33. Thereupon the circuit connections become the same as at theinstant switch 52 was closed, and as long as the switch remains closedthis same cycle of operation will take place repeatedly. The function ofthe contactor 20 also can be performed by other suitable means.

Modification of Fig. 3

Figure 3 illustrates the signal system of Figure 1 (similar referencecharacters indicating corre-.

spending parts), except that the auxiliary battery B2 and generator IBIare replaced by an alternating-current source comprising a transformer3i5 with its secondary coil 352 connected in the shunt or parallel path.The primary coil 35| of the transformer is connected to the main batterySil (when switch 52 is closed) through interrupter 310, whiclr isactuated by means hereinafter described, at a frequency suitable foreffective transformer and signal action. I have found this interruptionfrequenc to range from about 25 to. 100 per second, preferably of theorder of 50 per second. 'I'he interrupter frequency need not have afixed relation to the frequency of the signal modulation, but ispreferably at least five times as great. Upon the making and breaking ofthe current through the `primary coil 35|, alternating currents areinduced in the secondary coil 352. The valve bridge, consisting ofelectric valves 242, 243, 244 and 245, permits the passage of both thehalfcycle currents in the direction adding to the voltage of battery 60(during the intervals when contacter 23 is closed) and thus the voltageon signal lamp is increased by full-wave rectica-` tion.

Under some conditions single wave rectification is sucient, in whichcase three of the four valves are omitted, and the remaining valve, 242for example, is connected in lead |93 and lead |92 is connected tocontact 32.

Modification of Fig. 4 (a variation of Fig. 3)

The transformer may have separate primary and secondary coils asillustrated in Figure 3 or, as illustrated in Figure 4, these coils maybe connected as an auto-transformer. between separate or combined coilsdepends upon various conditions, for example, the utilization of anothersource for transformer supply than the battery 33 which would requireinsulation therefrom.

Figure 4 also illustrates two one-way electrical valves 242 and 243connected respectively in the outside secondary coil connections 32 and93 for the positive polarity auxiliary supply lead and the intermediateor tap connection 91 for the negative polarity auxiliary supply lead,which is also one of the primary leads. This valve and coil connectionarrangement provides supply of current from the secondary coil 352 intothe signal circuit (when contacts 3|, 32 are closed) during both theintervals when the primary current is being made and broken, and also iscommonly known as double-wave rectification.

In case the transformer primary is supplied from an alternating-currentsource instead of from an interrupted direct-current source, theinterrupter Sill can be omitted and the intermediate-tap 9i' generallywill be connected at the mid-point of the secondary coil, that is,equidistant from leads |32 and 93. With interrupted direct-currentsupply, the tap may be suiiiciently displaced from the mid-point tosubstantially equalize the effective direct-current voltages in eachhalf wave, and this is preferable with the lower frequencies ofinterruption.

As the interrupter 373 makes and breaks the current through therelatively high inductance of the primary circuit, if its contactsy areSubject to rapid wear or burning under such duty, the connection of acondenser 53 across the terminals of the primary coil 35! (Fig. 3) oracross the interrupter' (Fig. 4) is desirable.

Figure 4 also illustrates at numeral il a current limiter, in serieswith the primary coil 35|. This is useful under some conditions, forexample, to limit the flow of direct-current through the primary coil,in event that the interrupter should become inoperative in the closedposition, and to prevent greatly increased primary coil currentdetermined only by the resistance thereof.

I have found suitable for the current limiter a motor vehicle typetungsten lamp of rated current capacity severai times as great as thenorrnal effective primary coil current, because of the The choice greatincrease in filament resistance, With moderate increase in currenttherethrough.

Contacter and interrupter of Fig. 5 (for use in Figs. 3 and 4) Figure 5illustrates a combined contactor and interrupter device iaiordingcertain advantages when used with the lembodiments of Figures 3 and 4.

The motor 430 (illustrated conventionally with armature` 43! and field432) is energized from thebattery 6i] when switch 52 is closed. Formoto-r vehicle signal purposes I have found that motors such, forexample, as are commonly utilized to joperate small fans, and the like,are suitable forjcontactor and interrupterdrive, as they are small andreliable, and operate at speeds of the order of 40 to 100 revolutionsper second. The motor shaft 334 is electrically connected to the Wire 99(grounded for example as at 415). On the motor shaft 335 is mounted theinterrupter 310 consisting of a cylindrical insulating drum 335, ametallic segment 336 comprising part of the periphery of the drum andelectrically connected to the motor shaft at 450. A brush 33'! bears onthe periphery of the drum. The primary coil circuit is therefore madeand broken once for each revolution of the motor shaft.

Also on the motor shaft is mounted a worm -329 which engages with a wormgear 323 that drives contactor 326. The Worm gear 323 is mounted onshaft 321 and also mounted thereon, but insulated therefrom, is brusharm 326 carrying contactor brush 33| energized from transformersecondary 352. Also, insulated from arm 326 and the frame of the Vehicleis contact 332, connected to Wire 'Il and arranged to be contacted bybrush SSI, as the brush rotates, say in a clockwise direction. Undersome conditions, the use of a shunt-Wound motor may be preferable andother alternative means of driving the interrupter-contactor, such, forexample, as speed-governed drive from the vehicle engine, or the like,may be used.

The brush 33B and the contact 332 are equivalent in function to` thecontacts 3l and 32 of the foregoing figures. The number of teeth of theWorm gear determines the contactor speed and therefore the frequency ofsignal modulation.

Numeral v324 indicates a dead or spacer contact surface over which brush33! passes.

It is apparent that the apparatus and methods of Figures 1 to 5 areadapted for the modulation of one or more signal lamps selectively orsimultaneously, and for single or dual purposes, and that the varioussignal effects may readily be produced, for example, those described inmy co-pending application Serial No. 44,941, led October 14, 1935, forSignal, eventuated into Patent No. 2,125,668, dated August 2, 1938.

It is to be understood that the electric valves or rectiers describedherein may each consist of one unit or of a plurality of units connectedin series, parallel or series-parallel, as may be required by thecurrent, voltage, and other characteristics of the signal circuit.

In View of the abo-ve, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructionsWithout departing from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanyingdrawings shall'be interpreted as illustrative and not in alimiting sense.

vI claim:

. 1. A signalling systeml comprising a signal means, a source ofelectric energy, a circuitconnecting said source and said signal means,a shunt in said connecting circuit, an interrupter in the shunt, abattery in said shunt, and means permitting only one-way oW of currentthroughv said connection, the shunt connections being to opposite sidesof said one-Wai7 current limiting means.

2. A system including a source of direct current, a signal means, acirucit connecting said source and said signal means, a shunt in saidconnection, an interrupter and a rectier in the shunt, means forsupplying current to the shunt and means preventing short circuiting ofthe shunt through said connection.

3. A system including a source of current, load means, a main circuitconnecting said source and said load means, a shunt circuit in parallelwith one lead of the main circuit, means in the shunted portion of saidlead preventing short circuiting of the shunt circuit through the lead,an interrupter in the shunt circuit, a bridge rectifier in the shuntcircuit and supplying current to the interrupter, a transformer having aprimary Winding and a secondary Winding, said bridge rectier beingconnected to receive current bothfrom the secondary Winding of saidtransformer and to receive current by a'connection ley-passing thetransformer, the primary winding of said transformer being connectedacross the main circuit, ,and current-changing means in the last-namedconnection. .5

4. A system including a source of direct current, load means, a maincircuit connecting said source andl said load means, a shunt circuit inparallel with one lead of saidmain circuit, means inthe shunted portionof said lead preventing short circuiting of the shunt circuit throughthe lead, a first interrupter in said shunt circuit, and anauto-transformer connected therein havinga primary Winding and asecondary Winding, the primary Winding being `connected across said maincircuit, a second interrupting means in said primary-Winding connection,the secondary Winding of said auto-'transformer being connected to andvfeeding said iirst interrupter, and current-rectifying means in saidconnection between the auto-transformer and the iirst interrupter.

5. A system including a source of direct current, load means, a maincircuit connecting said source and said load'means, a shunt circuit inparallel with one lead ofsaid maincircuit, means in the shunted portiono'f said lead. preventing short circuiting of the shunt circuit throughthe lead, an interrupter in said shunt circuit, and an auto-transformerconnected therewith having a primary Winding and a secondary Winding,means for supplying a varying current to the primary Winding, andcurrent-rectifying means in connection With said secondary Winding.

6. A signal system including a source of difrect current, signal means,a circuit connecting said source and said signal means, means in onelead of said circuit resisting flow of current in a direction from thesignal means to the source, a shunt circuit around said resisting means,means adapted to send a shunt current through said shunt circuit fromthe source toward the load means and around said resistance, and aninterrupter in said shuntcrcuit.

7. A signal system including a source of direct current, signal means, acircuit connecting said source and said signal means, means in one leadof said circuit resisting flow of current in a direction therein fromthe signal means toward the source, a shunt circuit around saidresisting means, means adapted to send a shunt current through saidshunt circuit from the source toward the load means and around saidresistance, an interrupter in said shunt circuit, and means preventingflow of shunt current through the shunt circuit in a direction from theload means toward the source.

8. A signal system including a source of direct-current, signal means, acircuit connecting said source and said signal means, valve means in onelead of said circuit permitting flow of current therein but resistingreverse flow of current, a shunt circuit around said valve means,

means adapted to send a current aiding said source through said shuntcircuit between the source and the signal means and around said valvemeans, and an interrupter in said shunt circuit.

9. A signal system including a main source of current, load means, acircuit connecting said source and said load means, a resistor in onelead of said circuit, a shunt circuit across said resistor, and anauxiliary source of current and an interrupter in said shunt circuit,said auxiiary source of current being `connected in a voltage-additiverelation to the main source of current as referred to the load means,whereby the voltage on the ioad means, when said interrupter is closed,is greater than the voltage of the main source.

PHILIP H. CHASE.

